<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div id="app"> 
        <button @click="fn">显示或隐藏</button>
        <div v-show="isShow">
            {{ msg }}
        </div> 
    </div>
    <script src="https://cdn.jsdelivr.net/npm/vue@2.7.16/dist/vue.js"></script>
    <script>
        const app = new Vue(
            {
                el: "#app",
                data: {
                    msg: "Lucy",
                    isShow: true
                },
                methods: {
                    fn() {
                        // this 会指向app
                        this.isShow = !this.isShow
                    }
                }
            }
        )
    </script>
</body>
</html>